Perforating gun



Jan. 3, 1939. H. c. YARBRoUGH PERFORAT I NG GUN Filed May 15, 1935 5 Sheets-Sheet 1 Jam-3, 1939. H. c. YARBROUGH PERFORATING GUN Filed May 15,11955 5 Sheets-Shes?l 2 Jan. 3, 1939. H. c. YARBRouGH 2,142583 PERFORMING GUN Filed May 13, 1935 5 Sheets-Sheet 5 A TT'o/e/VEY Jam 3, 1939 H. c. YARBROUGH y 2,142,583

PERFORAT I NG GUN Filed May 1s, 1935 5 sheets-sheet 4 INI/ENTOR ATTORNEY AfA/20w 0. WEB/@UGH Jan 3, 1939 H. c. YARBROUGH ,2,142,583

PERFORAT I NG GUN Filed May' 1s, 1935 5 sheefs-sheet 5 IJEJ/45 gm f DE .Fu/l nf gm NVENTOR HARM@ c'. WEeoI/Gf/ BY Z( M A TToR/VE Y Patented Jan. 3, 1939,

UNITED STATES PATENT OFFICE or, by mesne assignments to Lane-Wells Company, Los Angeles, Calif., a corporation of Delaware Application May 13, 1935, Serial No. 21,185

17 Claims.

This invention relates to a device for perforating metal and particularly pertains to a well casing perforating gun.

In the course of drilling a producing oil well it is often necessary to perforate the well casing after it has been set in the hole. Various mechanical structures have vbeen provided for this purpose, which structures are usually manipulated from above ground and the operation of which is often attendant by considerable difculty. Up to the present time various attempts have been made to perform perforations in well casing by the use of perforating guns which require a projectile to be forced from a gun barrel by an explosive charge. For the most part these operations have not been a success due to the fact that the enormous hydrostatic pressure of the iuid prevailing in the well and in the perforating zone causes a leakage of fluid into the powder chambers and renders the powder inert, or substantially so, and for the additional reason that since the powder is ignited by an electric charge of high voltage electricity led down to the tool through a supporting cable, the cable structure is not durable, so that it must be often replaced, and since this cable is very expensive its use is prohibitive.

It is the principal object of the present invention therefor to provide an oil well perforating gun which is simple in construction, is provided with a self-contained firing mechanism adapted to be actuated Within the gun by manipulation of a suspending member without the necessity of Aproviding a cable for conducting a ring current to the gun, the gun being so constructed as to` insure that uid under pressure will not force its way into any of the joints of the gun or into the firing chamber.

The present invention contemplates the provision of a perforating gun including a barrel section, a ring section, and a control section, which gun is adapted to be lowered into a well in any suitable manner and to thereafter by simple manipulation fire shots laterally into the circumscribing well casing as controlled from above ground, both as to the ring position and the ring operation.

The invention is illustrated by way of example in theV accompanying drawings in which:

Figure l is a view in longitudinal section showing the perforating gun assembled andvin ring position within a hole.

Fig. 2 is an enlarged view in longitudinal section showing the tripping mechanism by which the firing operation is controlled.

Fig. 3 is a view in transverse section through the tripping pawl showing its position relative to the tripping mechanism. 5

Fig. 4 is a view in diagram indicating the electrical arrangement of the gun and the manner in which its firing operation is controlled.

Fig. 5 is an enlarged fragmentary view showing the joint between the control section and 10 the ring section.

Fig. 6 is an enlarged fragmentary view showing the joint between the control section and the barrel section of the gun.

Fig. '7 is an enlarged fragmentary view show- 15 ing one of the barrels ofthe gun and indicating the detailed assembly ofthe gun when loaded.

Fig. 8 is an enlarged fragmentary view in longitudinal section showing the solenoid unit of the firing mechanism.' .0

Fig. 9 is a View in side elevation showing another form of the present invention.

Fig. 10 is an enlarged view in longitudinal section showing the conductor for the gun.

Fig. l1 is a view showing a wiring diagram of 25 the type of gun shown in Fig. 9, and in which separate electric relays are provided to control the ring circuits.

Fig. 12 is an enlarged view in end elevation showing the muzzle block.

Referring, more particularly to the drawings I0 indicates a well casing into which a perforating gun II is lowered. The perforating gun-com prises a control section I2, a ring section I3 and a barrel section I4. At the upper end of the control section a cable socket I5 is provided to receive a cable I6 by which the structure may be lowered into a well. At the lower end of the control section a threaded box member I1 is provided to receive the threaded pin I8 carried at the upper end of the ring section I3. At the lower end of the firing section I3 a threaded box member I9 is provided to receive a threaded pin 20 carried at the upper end of the barrel -45 section I4. The control section comprises a tubular casing 2I having mounted within it a trip pawl 22.y The trip pawl 22 is designed to pivotally connect with a shifting yoke 23 which reciprocates longitudinally within the tubular 50 member 2|. A guide pin 24 is secured to one end of the shifting yoke 23 and an operating rod 25 is secured to the opposite end of the shifting yoke. Interposed between the upper end of the yoke 23 and the shoulder 26 within the casing 2| is a spring 21 which acts against a collar 28 carried on the pin 24 and exerts pressure upon the yoke 23 in one direction. Interposed between the lower end of the yoke 23 and the shoulder 29 within the casing 2| is a. spring 30 which tends to move the yoke in the opposite direction. The springs 21 and 30 counterbalance each other to hold the yoke 23 in a normal intermediate position, at which time thepawl 22 will project outwardly through a slot 3| in the side wall of the member 2| and into the path of travel of a trip sleeve 32 which is free to reciprocate upon the tubular member 2| a suicient distance to allow the tubular member 2| and the pawl 22 to pass through the sleeve 33 and lengthwise thereof. 'I'he sleeve 33 is fitted with longitudinally extending bow springs 34 which are secured to the sleeve 33 and when fixed will produce a yielding gripping action within the casing sucient to hold the sleeve and the springs against movement unless positively moved by the gun body. The rod 25 reciprocates longitudinally within the tubular member 2| as actuated by movement of the pawl 22. This pawl ls articulately connected to the yoke 23 and when it encounters the sleeve 33 in either an up or down stroke it will act to similarly move the yoke 23 and the rod 25. The rod 25 at its lower end carries a bar magnet 35. 'I'his magnet will be moved downwardly to engage a brass plug 36. The plug 36 is threaded into a tapered hole 31 formed centrally of the pin l1. The upper end of the plug 36 has a conical point 38 which projects into a conical seat 39 of the bar magnet 35 when the magnet is moved to its lowermost position. Disposed within the plug 36 and extending longitudinally thereof is a passageway 40 which receives a small floating magnetic bar 4|. The lower end of this bar is connected with an operating rod 42 which is secured to a switch lever 43 by which an electric circuit may be completed from a Contact point 44 carried atthe lower end of the plug 36, to a contact point 45 carried upon the free end of the switch member 43.

The ring section I3 is tubular and carries a main electric battery 46 and a ring battery 41, as well as a time clock 48, and a selective switch unit 49. The battery 46 is provided with a lead wire 50 which is attached to the contact 45 on the free end of the switch member 43. The switch member 43 is formed of dielectric material so that when the contact 45 engages the contact 44 a circuit will be completed through a wire 5| to ground indicated at 52. The ground side of this circuit also connects with a wire 53 leading to a condenser 54 and a rheostat 55. The rheostat is in turn connected with the wire 50. The opposite side of the main battery 46, which may be of a voltage of the order of sixty volts, is connected with a conductor 56 leading to a switch Contact 51. A switch blade 58 may move toward and away from said contact as actuated by suitable mechanism of a time clock diagrammatically indicated at 48. The time clock 48 may be of any desired construction, and is provided so that there Will not be any possibility of a complete circuit within the apparatus before the gun is lowered to its ring position within the hole. The switch blade 58 connects with a main feed line 59 which leads to one side of a solenoid coil 60. 'I'he opposite side of this coil connects with a conductor 6| leading to a safety contact 62 which is engaged by a contact pin 63 mounted within a threaded member 64, This member may be removed from the iiring unit i3 when not in use. The wire 6| also connects with a wire 65 which leads to one pole of the ignition battery 41. This battery is of relatively low voltage and is designed for use in igniting the ring charges, as will be hereinafter described. The opposite side of the battery 41 is provided with a conductor 66 which leads to a contact '61 carried at the lower end of a solenoid sleeve 68. A contact 69 is carried on an end disc 10 of the solenoid coil 68 and is engaged by the contact 61 upon impulse of the solenoid. The solenoid sleeve carries an extension 1| which projects upwardly through an upper disc 12 of the solenoid coil 60. This extension carries a head 13 within which a yieldable pawl 14 is mounted. The pawl 14, as more clearly shown in Fig. 8 of the drawing, is provided with a point having a relative under face and which pawl is urged outwardly by a spring 15. The point of the pawl engages serrations 16 formed throughout the length of a connector rod 11. This rod reciprocates through the solenoid sleeve 68 and is guided by a nonmagnetic bushing 18. The opposite sides of the rod are formed with transverse serrations 16, all of which have holding shoulders face downwardly so that as the rod is lifted increment by increment it will be held against a lowering action by the pawl 14 and a pawl 19 mounted in a head 88 and carried upon the upper solenoid disc 12. Disposed longitudinally of the rod 11 and upon opposite sides thereof are a plurality of pairs of contact fingers 8| and 82. The fingers 82 are here shown as connected to a common .Feed wire 83 which is connected at its lower end to the contact point 69. IThe complementary iingers 8| of each pair are provided with lead wires 84 through which a circuit is conducted to an individual ring unit 85, as indicated in Fig. 7 of the'drawing. The wires 84 are led through passageways 86 within the body 81 of the barrel unit 4. These wires may be suitably connected with screws 88 which are led through insulating plugs 89 and to which screws an outside feed wire 90 leads to the firing unit. The ring units, as shown, comprise a removable muzzle section 9| and a replaceable firing charge section 92. The muzzle member 9| is made of especially treated steel and is formed on its outer face with an especial thread 93 which has a square lateral face 94 and an inclined back face 95. This threaded portion4 engages a complementary threaded section in the bore 96 of the barrel unit I4. Circumscribing the muzzle 9| at a point adjacentits outer end is a groove 91 which receives an annular packing ring 98. This ring sets within the groove and extends laterally thereof to fit tightly along its outer circumferential edge within the bore 96. The outer face of the packing ring is formed with an annular V-shaped groove 99 by vwhich the ring is expanded in position due to the fluid pressure acting against it. Attention is directed to the fact that one of the main problems in the construction of a casing perforating gun is to exclude the uid of the well from the firing chamber 92. For this reason the threads of the muzzle 9| are formed as here shown and the packing ring 98 is provided. The muzzle 9| is screwed into position against a bottom face |08 of the bore 96. it having iirst been iitted with a projectile |0l. This projectile is preferably made of high grade steel and acts as an electrical conductor when the firing current is completed. The outer end of the projectile ||l| is formed with a conical point |82 while the cylindrical body of the projectile is wrapped with a layer of Cellophane which will act as an electrical insulator after which the projectile with its Cellophane wrapper is forced into position within the muzzle bore |04. Connected to the point |02 of the projectile is a sti steel spring |05 which also connects with |06. This screw is threaded through a packing disc |01. The disc |01 is preferably made of laminated Bakelite and is forced into a counterbore |08 at the outer end of the muzzle 9|. |06. The spring |05 thus acts as a conductor for the electric current, as well as. provides a member for forcibly holding the projectile in its innermost position within the bore |04. The flring charge section 92 is mounted within a firing chamber |09 which is formed within the barrel body I4 as a continuation of the muzzle bore 96. A counterbore ||0 is formed around the mouth of the firing chamber |09 and communicates with the muzzle bore 96. The bore |09 is lined witha layer of` insulating material I II by which the ring section or unit 92 is insulated against the actionof moisture which might otherwise enter into the explosive charge. The firing unit 92 comprises a cylindrical container I I2 preferably made of Bakelite and in to the lower end of which is pressed an end wall II3. At the opposite end an end wall |I4 is pressed and within the container thus formed there is an explosive charge. A spring contact member I|5 carried on the end wall |I3 engages the end face of the bore |09. This contact member is secured to the end wall by a pin II6 which extends into the container. A contact member II1 is carried upon the opposite end wall II4 by a pin |I8 which extends into the explosive charge. The pins II6 and IIB are connected by a fuse wire |I9 which is of sulcient resistance to the ow of current to become heated and to thus ignite the charge through which it passes. The contact member II1 rests against the under face of a metal cup which is convexed and is of a diameterto snugly iit within the bore I|0. This cup extends with its open mouth circumscribing the outer en'd. of the wall ||2 of the explosive charge container. A metal ring I2I is formed with its inner face concaved to conform to the contour of the convexed outer face of the cup |20. The ring I2I is substantially triangular in cross section, having a cylindrical outer wall |22 agreeing substantially with the wall of the counterbore |I0, and a flat face |23 against which the inner face |00 of the muzzle is pressed. The ring I2I has a central opening |24 agreeing substantially with the diameter of the bore |04 within which a projectile |0| is placed. Interposed between the concave face of the ring I2I and the convex face of the cup |20 is a layer of uid packing |25 which prevents the leakage of uid into the bore |09. The ring |2I due to its central opening discloses the end of the cup |20 and makes it possible for the force of the explosive charge to shear a circular hole through the cup when the explosive force has reached a desired amount. An extending tip |26 formed on the end of the projectile |0| contacts with the disclosed end face of the cup |20 so that the electric charge may pass from the projectile to the cup I20-and then to the contact member II1.

In order to insure that the electrical connections of the firing unit I3 are not injured by moisture or liquid which might force its way into the interior of the firing unit the connection between the ring unit I3 and the barrel unit I4 is of especial construction, as particularly shown The conductor 90 is attached to the screwin Fig. 6 of the drawings. Here it will be seen that at the lower end of the section I3 a plug or cylinder |21 is provided and is pressed into a counterbore. 'Ihis cylinder is preferably made of l-aminated Bakelite through which pins |28 extend. The upper ends of these pins are threaded and fitted with nuts |29 by which the various electrical conductors 84 are attached. Openings |30 occur within the member |21 at the lower ends of each plug. These openings receive a connecting pin |3|. The pins I3I project from the end of a plug |32 which is of similar construction to the plug |21. The pins I3I are continuations of the upper end of pins |33 which are longitudinally tapered and driven into positionwithin the plug |32. The lower ends of the pins project through the plug |32 and are threaded to receive nuts |34 which carry the extensions of wires 84 leading to the individual muzzle units.

In operation of the form of the invention shown in Figs. 1 to 8, inclusive, the structure is assembled as shown in Fig. 1, and the ring units 85 are loaded and assembled as shown in Fig. 7. At this time the safety member 64 is removed from its'positlon in the outer wall of the iiring section I3. The sleeve 33 with its springs 34 are positioned at the upper end of their path of the travel on the control member I2, and when it is desired to place the gun in a well preparatory to ring the member 64 is screwed into position so that a ground contact will be made from conductors 6| and 65. The device `ls then lowered into the well. During the lowering operation the springs 34 will hold the sleeve 33 at the top of the stroke since the springs will engage theside .walls of the casing I0. When the gun has been lowered to the desired position for firing the entire structure may be lifted until the p-awl 22 encounters the under face of the sleeve 33, it being understood that this sleeve will be frictionally held against motion by engagement of the springs 34 with the casing. As the structure is further raised the pawl will force therod downwardly and will move the permanent bar magnet 35 into engagement with the point end 38 of the plug 31, which plug extends upwardly at the upper end of the firing unit. The magnetic iniiuence of the bar magnet 35 will thus exert a lifting action on the magnetic b-ar 4I so that the rod 42 will be raised. Th s will complete an electric circuit through the witch member 43 to ground, and at the same time will establish a circuitl from a wire 50 which leads to a source of electric energy 46, such as a dry cell batteryenclosed within the firing unit. During the interval of time required for lowering the gun into the well the timing clock 48 will hold switch member 58 from engagement with contact 51, but at the time the ring manipulation takes place the clock 48 will have permitted the lever 58 to move to a contacting position with the member 51 so that the other side of the circuit including the battery 46 will be completed to a conductor 59 leading to the solenoid coll 60. This circuit will then continue to ground through a conductor 6I. When the circuit is thus completed the solenoid coil 60 will be energized and will tend to move the rod 11 upwardly. This upward movement will be limited by physical engagement of contact 61 and 69 which will complete an electric circuit from a battery 41 along a wire 66 to.the battery and then along the wire 65 from the battery. 'I'he circuit from wire 66 through the contact 61 and through the contact 69 will continue along the wire 69 leading to each of contact fingers 82 and thus provide a common supply for these ngers. The initial movement of the rod 11 will bring the contact element 82' into a position to establish a circuit from members 82 to members 0| and thence along a Conductor 84 of the particular contact 8| to the desired ring unit 05. The circuit will then be completed through the wire 06 to the screw |06, and then -along spring |05 to the projectile |0I, after which it will flow through the cup member |20 to the contact II'I and thence through the fuse wire I I9 to the ground. The fuse wire will ignite the charge of powder within the member 92, but due to the manner in which the cup |20 is positively held over the mouth of the firing chamber the burning powder will be confined until enormous pressure has been stepped up. At that time the explosive force of the charge will cause a center disc of the cup |20 to be forced through the central opening |24 of the met-al ring |2| and against the muzzle block 9| and sheared clear of the cup. The explosive force will then act upon the projectile |I to force it outwardly through the packing disc |01. It will be recognized that due to the retarding action of the explosive charge as brought about by the cup |20 and the ring |2I, a high degree of eiiciency can be obtained even though the structure is limited to a very short muzzle. It will further be seen that by the arrangement here disclosed the explosive charge will be adequately protected from the pressure of the fluids in the well. After one of the muzzles has been fired the successive muzzles may be red by rising and again lowering the gun with relation to the sleeve 33 and the springs 34 which with the sleeve is held in a set position Within the casing. After the sleeve and the control section of the gun have been restored to their original position the gun structure may be adjusted to assume a different position within the well casing, after which the gun m-ay be fired again. It will be noted that due to the solenoid 60 the rod 11 Will be moved upwardlya determined amount each time the solenoid is energized. The members 14 and 19 will act to engage the serrations on the rod 11 and will hold the rod in its upwardly moved position. In this manner the rod will move by increments at each impulse of the magnet 4| so that a step by step action will take place to completecircuits through the successive sets of contacts 8| and 62, which contacts control the separate ring circuits. By this arr-angement it will be seen that it is not necessary to provide any electrical cable or conduit for leading anelectric current to the device, and that the selfcontained gun structure m-ay be actuated by a simple mechanical operation initiated from above ground.

Referring particularly to Figs. 9, 10, and 11 of the drawings a somewhat different electrical ara firing se'ction IM and the previously described barrel section I4. 'I'he control section |40 is formed with a longitudinally extending slot |62 in its side wall and within which slot a plurality of electric contact members |03 are fitted. These areasss members are preferably spaced equidistant from each other lengthwise of the slot and are connected with a series of electric conductors |44 which are shown more in detail in Fig. 11 of the drawings. The upper end of the cylindrical control member |40 is fitted with a rope socket I5 and its lower end is threaded into the cylindrical casing |45 of the firing unit |4|. The connection between the units |40 and |4| is a threaded connection, and since the control unit |40 carries a plurality of conductors |44 through which circuits must pass to the firing unit |4| the plug and the socket members |21 and |32 are provided as shown in Fig. 6 of the drawing. This will prevent leakage into either of the units. Slidably mounted upon the body of the control unit '|40 is a sleeve |46 similar to the sleeve 33 previously described as being mounted on control unit |2. I'his sleeve carried bow springs |41 which engage the Wall of the casing I6. At the lower end of the sleeve a threaded sleeve nut |48 is provided. This nut has an overhanging end wall |49 which engages an annular flange |50 of a contact tube The inner diameter of the contact tube |5| is slightly larger than the outer diameter of the body of the control unit |40. Due to the method of connecting the members |5| and |48 the tube I5| may have rotational movement with relation to the sleeve. The tubular member |5| carries a spring contact |52 within it, said contact being designed to project into the longitudinal slot |42 in the side face of the control unit |40 and to contact the members |43 when in register therewith. It will be evident that due to the fact that the contacts |43 are set into the recess |42 there will not be any damage to them as the device 1s lowered through the well casing and its joints. The ring unit |4| carries relay batteries |53 and ring batteries |54. It is also desirable that a timing clock |55 be provided. The ring unit also includes a plurality of firing relays |56 and an initial circuit relay |51. The coils |56 of the various relays |56 are connected on one side of the conductors |44 previously described as leading to the control unit. 'Ihe opposite sides of these magnet coils are connected to a common lead Wire |50 which in turn is connected to a contact |60 of the initial control relay |51. The contact |60 is carried on the armature |6| of the relay. coil |62 which would draw the contact |60 down- Wardly and make an electrical connection with the contact |63. n A conductor |64 connects con tact |63 with one pole of therelay battery |53. The opposite pole of the battery is connected to a ground Wire |65. One side of the magnet coil |62 of relay |51 is connected with a ground wire |66. The opposite side of this coil is connected With a Wire |61 which leads to a common leadvwire |68 for the switches of the various firing relays. contact |69 of the time clock |55. Another contact of the clock is connected with a wire |1| which in turn is secured to one pole of the rlng battery |54. The opposite pole of the firing battery is connected to ground by Wire |12. The wire |60 provides a common lead wire for each of the firing relays |56. Separate wires |13 conneet the lead wire with contacts |14. Movable contacts /may be brought into engagement therewith, these contacts being carried on the armatures |16 of the relays |56. 'I'he movable contacts |15 are secured to separate wires '|11, one of which leads to each of the ring units 85.

In the operation of the form of the invention This armature is energized by magnet The lWire |68 connects with one.

position for firing operation will be delayed if necessary until the time clock |55 has moved the contacts |69 and |10 together. The firing battery |54 will then be electrically connected tothe common supply line |68 for the firing relays. This will also supply an initial circuit to the wire |61 leading to the relay |51. This will energize magnet |62 and will connect the relay battery wire |64 with the lead wire |59, for each of the ring magnets. Circuits will then be partially completed through conductors |18 from the lead wire |59 through the relay magnets |58 and to the separate relay wires |44. As the tool is then drawn upwardly the sleeve |46 'carrying the bow springs |41 will remain stationary and the control unit |40 will be lifted through the sleeve |46. 'I'his will successively move the contact member |52 into engagement with the contacts |43 which are positioned along the longitudinal slot |42. As these contacts are successively engaged by the member |42 the relay circuits through conductors |44 will be successively closed by being grounded. This will successively energize therelay magnets |58 of the several iiring relays |56 and will complete electric circuits from the ring battery |54 through conductor |68 to contacts |14 and |15, and thence through conductor |11 to the individual firing units where the circuit will be completed in the manner shown in Fig. '1 of the drawings.

It will thus be seen that by the structure here disclosed it is possible to lower a perforating gun into a well, the gun being equipped to produce a large number of perforations which may be selectively made through the wall of a well casing at the option of the operator, and with the assurance that the powder will be maintained in a suitable firing condition and will provide an explosive force suicient to cause a perforation to be made in a well casing and further `penetration of the surrounding earth formation. It will also be evident that by the arrangement here shown it is unnecessary to utilize highvoltage current in carrying out the present invention. Consequently, although the contacts |43 are exposed to well uid which may be semi-conductive, the resistance of such liquid to low voltages is suicient to prevent ignition of the powder i charges. Furthermore it is unnecessary to provide expensive cable for conducting an electric current to the gun from above ground, and which cable has the additional objection of becoming readily worn and useless.

While I have shown the preferred form of my invention, as now known to me, it will be understood that various changes might be made in the combination, construction, and arrangement of parts, by those skilled in the art, without departing from the spirit of the invention as claimed.

`Having thus described my invention what I claim and desire to secure by Letters Patent is:

l. A perforating gun, suspending means for lowering the gun and positioning it within a well i bore, muzzles carried by the gun to receive a projectile and an explosive charge and to direct it laterally of the gun, self-contained electrical firing means for igniting said charges, an enclosure for hermetically sealing said iiring means within the gun structure, and means responsive to manipulation of the suspending means for reciprocation with respect to .said gun, and a device for translating such reciprocation through said enclosure to operate said ring means.

2. A perforating gun, suspending means for lowering the gun and positioning it within a well bore, muzzles 'carried by the gun to receive a projectile and .an explosive charge and to direct it laterally of the gun, self-contained electrical firing means for igniting said charges, said ring means being hermetically sealed within the gun structure, contacts therefor exposed to the exterior of the gun, and a firing means including a cage engageable with the surrounding casing and shiftable axially with respect to the gun upon reversal in movement of the gun, and a contactor carried by said cage for engaging and closing said contacts upon such reversal.

3. A perforating gun adapted to be lowered into a well on a suspending member, said gun having a barrel section within which a plurality of muzzles are formed, theA muzzles being adapted to direct projectiles laterally of the gun by explosive force, electric means for igniting explosive charges in each of the muzzles, an enclosure hermetically sealing said means within the gun structure, a magnetic device operable through said enclosure'to actuate said means, and a mechanical device manipulated by movement of the suspending means to control said magnetic device.

4. In a gun structure adapted to re an explosive charge while submerged within a uid under pressure which structure comprises a muzzle, a projectile and explosive charge hermetically sealed therein, firing means sealed therein, and magnetic means acting magnetically through the casing of the gun to initiate operation of the ring means.

5. A perforating gun adapted to be lowered into a` well and including a hermetically sealed chamber and ring mechanism contained within said chamber and having a magnetically responsive operating element, and a movable magnet 1ocated exteriorly of the said chamber and operating magnetically through the wall thereof for actuating the magnetically responsive member.

6. A perforator gun comprising: a body structure having a gun unit and a ring mechanism; means for lowering and raising said body structure in a well bore; a device carried by said body structure and engageable with the well bore to move axially on the body structure upon lifting the body structure subsequent to lowering the same; and an instrumentality operatively associating said device with said ring mechanism.

7. A gun'perforator comprising: a body structure having a plurality of laterally directed gun units, and a firing mechanism adapted to operate said gun units in sequence; means for lowering and raising said body structure in a well bore; and an operating device for said firing mechanism carried by said body structure, said operating device being engageable with the well bore and initially positioned to move axially relative to said body structure upon lifting thereof after being lowered thereby to operate said ring mechanism.

8. A casing perforating gun comprising a gun body having a laterally directed gun unit; a. selffor said gun unit, said ring unit including a magnetically responsive element; magentic means externally of the gun; and means for moving said magnetic means with respect to said element thereby to actuate said element to initiate operation of the ring means.

9. A casing perforating gun comprising a gun body having a plurality of laterally directed gun units; a hermetically sealed housing; a selfcontained electric firing unit in said housing for sequentially iiring said gun units including an element responsive toa magnetic eld actuating externally of said housing; magnetic means externally of the housing; and means for moving the fleld of said magnetic means into and out of influencing relation with said element to initiate operation of the iiring means.

10. A gun perforator comprising: a gun body having a plurality of laterally directed gun units; a sealed housing connected with said gun body; a self-contained iiring mechanism within said housing including electrical connections with each of said gun units, a source of electrical energy, a controller for effecting connection of said source with said gun units in sequence, and a magnetic eld responsive element for initiating operation of said firing mechanism; and a magnetic device externally of said housing and movable into and out of magnetic association with said element.

11. A gun perforator comprising: a gun body having a plurality of laterally directed gun units; a sealed housing connected with said gun body; a self-contained ring mechanism within said housing l including electrical connections with each gun unit, a source of electrical energy, means for connecting said source with said gun units in sequence, and a plurality of contacts for said means exposed to the exterior of the housing; and a device engageable with the surrounding wall of a well bore to move relative to said housing and engage said contacts.

12. A gun perforator comprising: a gun body having a plurality of laterally directed gun units; a sealed housing connected with said gun-body; a self-contained firing mechanism within said housing including electrical connections with each gun unit, a source of electrical energy, means for connecting said source with said gun units in sequence, and a plurality of contacts for said means exposed to the exterior of the housing; means for lowering and raising said body structure and housing in a well bore; and an operating device for said firing mechanism carried by said housing, said operating device being engageable with the well bore and initially positioned to move relative to said housing upon liftcontained, hermetically sealed electric ring unit`v ing thereof after being lowered thereby to engage and close said contacts.

13. In a gun perforator: a gun body having explosive receiving chamber and a barrel receiving recess communicating therewith; a gun barrel for said recess; an insulated bullet fitting said gun barrel; an insulated closure for the outer end of said gun barrel; a current supply lead extending through said closure and connected with said bullet; and an electrically fired cartridge grounded at one end and electrically connected at its other end with said bullet.

14. An apparatus for perforating well casing embodying: a body adapted to be suspended in the casing and having a transverse chamber therein; a cartridge in said chamber adapted to be red through said casing; a sleeve member on said body; means associated with said sleeve and operative during relative movement between said sleeve and said body for firing said cartridge; and means on said sleeve engaging the interior of said casing for restraining said sleeve against movement relative to said casing.

l5. A perforating gun comprising a barrel section having a plurality of laterally directed muzzles, electric firing means self-contained within the gun and connectable individually with the muzzles for firing charges therein in sequence, suspending means for the gun, means engageable with said casing and manipulated by successive reciprocation of said suspending means for connecting the electric firing means with said muzzles in sequence.

16. In a gun perforator: a gun body having a. cartridge socket open at one end only; and a gun barrel receiving counterbore continuing from the open end of the chamber; an electrically fired cartridgev havirg a terminal grounded against the inner or closed en-d of said cartridge socket and an insulated end facing into the counterbore; a barrel tting said bore; a projectile fitting said barrel; and means incorporating said projectile for making an electrical connection with the insulated end of said cartridge.

17. An electrically red gun perforator comprising: a body member having a plurality of laterally directed gun units, eachincluding an electrically responsive cartridge, a gun barrel, and a projectile; leads for said gun units extending through said body member and outwardly thereof to enter the gun units through the muzzle ends of said barrels, and electrically associated with said cartridges; a source of electrical energy for said leads of sufficiently low potential that no material loss of energy occurs by reason of exposing said leads to electrolytic liquids; and controller meansl for connecting said source with said leads.

HAROLD C. YARBROUGI-I. 

